Tone modulator for musical instruments



March 10, 1931. J. H. HAMMOND, JR 1,795,649

TONE MODULATOR FOR MUSICAL INSTRUMENTS Filed Oct. 29, 1929 2 Sheets-Sheet 1 Fig. .7

53 .57 50 5/ J4 24 /J 32: 5a

a 6'25 /a- T7 E-- 1'5 3/ 2a 64 5/ 2a 024i; 2?

INVENTOR.

A TTORNEY March 10, 1931.

J. H. HAMMOND, JR 1,795,649 TONE MODULATOR FOR MUSICAL INSTRUMENTS Filed oct- 29, 1929 2 Sheets-Sheet 2 Fig. 4

k Ti/[EN TOR. I A m m 2 ATTORNEY Patented Mar. 10, 1931 PATENT OFFICE JOHN HAYS HAMMOND, JR., OF GLOUCESTER, MASSACHUSETTS TONE MODULATOR FOB. MUSICAL INSTRUMENTS Application filed October 29, 1929.

The invention relates to musical instruments and more particularly to a musical instrument of the percussive type.

The invention provides means for controlling the sound produced by a musical instru ment so as to effect a predetermined ratio of variation in intensity of sound with respect to movement of a control device associated with said instrument.

According to the present invention a musical instrument is provided such as a piano having a casing with one or more modulating reflectors arranged to control the emission of sound from within the casing. These modulatin reflectors are actuated in response to the operation of a. cam device which is operativelv connected to a control device such as a pedal. By the use of a cam device the rate of opening of said reflectors may be varied according to any law by using a correspondingly characterized cam- Any desired diminnendo or crescendo effect may be therelov produce-d.

In cases where a plurality of groups of reflectors are provided. each group may be successively controlled so as to produce a very delicate shade of tone. This is effected through the instrumentality of a cam device associated with each group of reflectors, each one of said cam devices being relatively characterized and mounted so as to produce any desired effect. and all of said cam devices being controlled from a sin gle control device.

The invention also consists in certain new and original features of construction and combinations of parts hereinafter set forth and claimed.

Although the novel features which are believed to be characteristicof this invention will be particularlypointed out in the claims appended hereto. the invention itself, as to its objects and advantages, the mode of its operation and the manner of its organization may be better understood by referring to the following description taken in connection with theaccompanying drawings forming a part thereof, in which Fig. 1 is a front elevation of a grand piano shown partly in section;

Serial No. 403,204.

Fig. 2 is a side elevation of a portion of the structure shown in Fig. 1;

Fig. 3 is a section taken on the line 33 of Fig. 2;

Fig. 4 is a top plan view of a portion of the mechanism of Fig. 1;

Fig. 5 is a bottom plan view of a portion of the mechanism of Fig. 1; and

Fig. 6 shows a modified form of the cam mechanism of Fig. 4.

Like reference characters denote like parts in the several figures of the drawings.

In the following description and in the claims parts will be identified by specific names for convenience, but they are intended to be as generic in their application to similar parts as the art will permit.

Referring to Fig. 1 of the drawings the invention is shown as applied to a grand piano 10 having a casing 11. For producing musical sound there is provided within the casing 11 a plurality of tuned strings such as 12, tuned to the notes of the musical scale. It will be understood that there may be provided for each note of the musical scale one or more such strings as may be desired, in accord ance with usual practice. The strings 12 are mounted in a usual frame 13, and for vi brating the strings for each of the notes of the scale, there is provided a percussive hammer action such as 14 operatively connected to a key 15 of the manual of the piano. A sounding board 16 is provided within the casing 11 and serves to divide the interior of the casing into two resonating chambers. A lyre 17 depends from the casing 11 and supports a pedal block 18 in a position conven ient to the feet of the musician. A plurality of pedals, shown three in number as at 19, 20, and 21 is mounted in the pedal block 18, and

the two right hand pedals 19 and 20 are connected to the sustenuto and loud pedal. actions of the piano in conventional manner, and having no bearing on the present inveution, it is thought they need not be further described.

The left hand pedal 2-1 is operatively connected to a Vertical reciprocating rod 22 slidably mounted at its upper end in a bracket 23, and engages at its upper end one arm of a bell crank lever 24. The bell crank lever 24 is pivotally mounted on a pivot pin 25 secured to the bracket 23. The opposite arm of the bell crank lever 24 is pivotally connected to one end of a link 26 the other end of which is pivotally connected to one arm of a horizontal bell crank lever 27, pivoted as at 28 (see Fig. 5) .to the frame of thepiano 10 The other arm of the bell crank lever 27 is pivotally con'nectedby means ofalin'k29to an arm 30 rigidly secured to a vertical shaft 31. This shaft is rotatably mounted in spaced bearings such as 32, 33 secured respectively to portions of the piano casing 11. There is provided on the shaft31 a collar 34 rigidly secured thereto as by pins thereon, for pre ventingthe shaft 31 from longitudinal displacement with respect to its bearings.

A cam is aiflxed to the shaft :31 below the lower wall of the casing 11 so as tolrotate with the shaft. A cam roller 41 engagesthe cam face of the cam 40, and is rotatably .mounted at one end of a reciprocating rod 42. The rod 42 is slida-bly mounted in a bracket 43 affiXedto the casing 10. A spring 44 is secured at one of its ends to the bracket 43, and at the other end to a boss 45 integral with therod 42, so as to maintain the roller 41 constantlyin engagementwith the cam face of the cam 40, The other end of the rod 42 is pivotally connected as at 46 to a connecting rod 47, which in turn is pivotally connected at spaced points with av plurality of arms 48, each of which is mounted upon one of the modulating reflectors forming the lower group and which will be more fully described hereinafter.

There is secured to the shaft 31 near the upper wall of the casing 11 a cam 50having in engagement with its cam facea roller 51. The-cam roller 51 .is mounted at one end of a reciprocating rod 52, which is slidably mounted in a member 53 which isrotatably mounted in a bracket 53 aflixed to the casing 11. A-spring 54 is secured at oneof its ends to the bracket 53 and at the other. end to aboss55 integral with the rod 52 soas tov maintain the roller 51constantly in engagement with the cam face ofthe cam 40. The other end of therod 52is pivotally connected as at 56 to-a connecting rod. 57, whichinturn is pivotally connected atspaced points with :a plurality of arms 58, each of which ismount- -ed upon one of the modulating sound wave reflectors such as 59 forming the upper group to be describedhereinafter.

The casing 11 is provided with oppositely disposed controllable apertures as at 60, 61.

u The interior face of the boundary walls of the casing is provided with a layer 63-of sound wave reflecting material such. 'as sheet aluminum. The upper reflectors 5-9 are each pivot- :ally mounted on their longitudinal axes in the upperaperture 60 of-the casing, thus serving to control the emission of sound through the respective aperture; each reflector 59 1s preferably in the form of an elongated flat member having bevelled edges and pivotally mounted to rotate about its longitudinal axis (see Fig. 2) and each reflector is provided on its inner face with a layer 62 of sound reflecting material such'as a sheet of metal.

The modulating mechanism is yieldingly mainta-ined in the position shown by a spring 64 having one end connected to the link 26 and the other end to a suitable fixed lug on the piano frame.

' In the modified embodiment of F 1g. 6, there is provided a cam mounted onthe shaft 31in place of the cam 40. By the use of a cam 50 for the upper closures, and of a cam of the kind illustrated in F 6 .for the lower closures, the emission ofsound from the two 1 resonating chambers may be independently controlled.

In the operation of theform of the invention shown in Figs. 1 to 5, when the pedal 21 is depressed the rod 22will be elevated, thus ro- .tatingthebell crank 24 in a counterclockwise direction, which in .turn willmove the link 26 to the left. This will cause the bellcrank 27 to be rotated in .a counter clockwise direc tion, as seen inFig. 5, which in turn will cause the arm 30 to be turned in thesame direction but through alarger angle. The arm 30 being rigidly secured to thershaft 31, will turn it ina counter clockwise direction as seen in Fig. 5, which will rotate the cams 40 and 50.

This motionof the cams ,40 and 50 will cause the ,rods42 and 52 .to'be moved to the right, which in turn will move the rods 47 and 57 alsotothe right,thus causing the tone control devices 59itofbeclosed. The shape of the cams vcan be suchthat they Will cause the tone control devices .to-be closed rapidly at first and then very graduallyat the end. suitably .formingthefaces of the name, any desired motion of the tone .modulators may be produced.

.The operation of the modified embodiment of Fig. 6 will, itis thought, be clear from the foregoing description. In this embodiment the use of diflerentlycharacterized cams the-device illustrated and in its operation may be made by those-skilled in the art without'deepa-rting from the spirit of the invention.

What is claimed :is: 1. A modulating system for a musical instrument of the percussive" type comprising a plurality of resonating :chambers, a plurality of sound modulating reflectors arranged in groups for variably controlling the volume of sound emitted from the different resonating chambers, a tone modulating pedal, a rod 5 operatively connected to said pedal, a single cam for each of said resonating chambers, operatively associated With said rod, and means engaging said cams for actuating said groups of reflectors respectively.

2. A modulating system for a musical instrument of the percussive type comprising a plurality of resonating chambers, a plurality of sound modulating reflectors arranged in groups for variably controlling the volume of sound emitted from the different resonating chambers independently, a tone modulating pedal, a rod operatively connected to said pedal, a diflerently characterized cam for each of said resonating chambers, said cams being operatively associated with said rod, and means engaging said cams for actuating said groups of reflectors respectively.

3. A modulating system for a musical instrument comprising a tone modulating control device, a plurality of sound wave reflec tors arranged in groups for variably controlling the volume of sound emitted from the instrument in different directions respectively, a single cam for each group of reflectors operatively connected thereto for controlling the reflectors, and means operatively connecting the cams with said control device.

4. A modulating system for a musical instrument of the percussive type comprising a tone modulating control device, a plurality of sound Wave reflectors arranged in groups for variably controlling the volume of sound emitted from the instrument in different directions respectively, a roller for each of said groups operatively connected to the respective reflectors, a cam for each roller actuated by said control device, and yielding means for maintaining each of said rollers in engagement with the respective cam.

In testimony whereof I have hereunto set my hand.

JOHN HAYS HAMMOND, JR. 

